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Diffstat (limited to 'boost/fusion/view/flatten_view/flatten_view.hpp')
-rw-r--r-- | boost/fusion/view/flatten_view/flatten_view.hpp | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/boost/fusion/view/flatten_view/flatten_view.hpp b/boost/fusion/view/flatten_view/flatten_view.hpp new file mode 100644 index 0000000000..aa47240771 --- /dev/null +++ b/boost/fusion/view/flatten_view/flatten_view.hpp @@ -0,0 +1,127 @@ +/*////////////////////////////////////////////////////////////////////////////// + Copyright (c) 2013 Jamboree + + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) +//////////////////////////////////////////////////////////////////////////////*/ +#ifndef BOOST_FUSION_FLATTEN_VIEW_HPP_INCLUDED +#define BOOST_FUSION_FLATTEN_VIEW_HPP_INCLUDED + + +#include <boost/mpl/bool.hpp> +#include <boost/mpl/single_view.hpp> +#include <boost/fusion/support/detail/access.hpp> +#include <boost/fusion/support/is_view.hpp> +#include <boost/fusion/support/category_of.hpp> +#include <boost/fusion/support/sequence_base.hpp> +#include <boost/fusion/sequence/intrinsic/begin.hpp> +#include <boost/fusion/sequence/intrinsic/end.hpp> +#include <boost/fusion/view/flatten_view/flatten_view_iterator.hpp> + + +namespace boost { namespace fusion +{ + struct forward_traversal_tag; + struct flatten_view_tag; + + template <typename Sequence> + struct flatten_view + : sequence_base<flatten_view<Sequence> > + { + typedef flatten_view_tag fusion_tag; + typedef fusion_sequence_tag tag; // this gets picked up by MPL + typedef mpl::true_ is_view; + typedef forward_traversal_tag category; + + typedef Sequence sequence_type; + typedef typename result_of::begin<Sequence>::type first_type; + typedef typename result_of::end<Sequence>::type last_type; + + explicit flatten_view(Sequence& seq) + : seq(seq) + {} + + first_type first() const { return fusion::begin(seq); } + last_type last() const { return fusion::end(seq); } + + typename mpl::if_<traits::is_view<Sequence>, Sequence, Sequence&>::type seq; + }; +}} + +namespace boost { namespace fusion { namespace extension +{ + template<> + struct begin_impl<flatten_view_tag> + { + template<typename Sequence> + struct apply + { + typedef typename Sequence::first_type first_type; + + typedef typename + result_of::begin< + mpl::single_view< + typename Sequence::sequence_type> >::type + root_iterator; + + typedef + detail::seek_descent<root_iterator, first_type> + seek_descent; + + typedef typename seek_descent::type type; + + static inline + type call(Sequence& seq) + { + return seek_descent::apply(root_iterator(), seq.first()); + } + }; + }; + + template<> + struct end_impl<flatten_view_tag> + { + template<typename Sequence> + struct apply + { + typedef typename Sequence::last_type last_type; + + typedef typename + result_of::end< + mpl::single_view< + typename Sequence::sequence_type> >::type + type; + + static inline + type call(Sequence&) + { + return type(); + } + }; + }; + + template<> + struct size_impl<flatten_view_tag> + { + template <typename Sequence> + struct apply + : result_of::distance + < + typename result_of::begin<Sequence>::type + , typename result_of::end<Sequence>::type + > + {}; + }; + + template<> + struct empty_impl<flatten_view_tag> + { + template <typename Sequence> + struct apply + : result_of::empty<typename Sequence::sequence_type> + {}; + }; +}}} + + +#endif |